Cerebrospinal fluid involvement in patients with adult acute leukaemia and non-Hodgkin's lymphoma.

One hundred and thirty-four cases of adult acute leukaemia and 212 cases of non-Hodgkin's lymphoma treated by the Combined Haematology Division of Sydney Hospital over a four year period were reviewed to establish the incidence of central nervous system (CNS) involvement. The sole diagnostic criterion considered was positive cerebro-spinal fluid (CSF) cytology. The detected incidences of 21% and 5 . 2% respectively in long term surviving adults with leukaemia and those with non-Hodgkin's lymphoma are similar to other series. Unusual findings were the relatively low incidence of involvement in acute myelomonocytic leukaemia and unexpectedly high incidence in diffuse poorly differentiated lymphocytic lymphoma. Cytocentrifugation using the Cytospin has proved to be a useful technique in detecting small numbers of abnormal cells in the CSF.